How the Default Probability is Defined by the Credit Portfolio Models : A Comparative Analysis between the Theoretical Structural Models?

This paper is elaborate of which the main is to present a theoretical analysis between the structural models. There are currently three types of models to consider the risk of credit: the structural models (The KMV Moody's model and the CreditMetrics model) also defined by the models of the value of the firm, reduced form models also defined by models with intensity (actuarial models) and the econometric models (The macro-factors models). The development of its three types of models is based on a theoretical basis developed by several researchers and many financial institutions. These models are dedicated to measurement the default probability of credit portfolio. The evaluation of their default frequencies and the size of the credit portfolio are expressed as functions of macro-economic and micro-economic conditions as well as unobservable credit risk factors, which explained by other factors. We developed three sections to explain the different characteristics of the structural models of credit portfolio management. The purpose of all its models is to express the probability of default